1. Technical Field
The present invention relates to a piezoelectric actuator, a motor, a robot hand, and a robot.
2. Related Art
As a motor for driving a driven member by vibration of a piezoelectric device, a motor that drives a driven member using an actuator formed by stacking a piezoelectric device having a rectangular flat plate shape on a reinforcing plate having an integrally formed projection by bringing the projection of the reinforcing plate into contact with the driven member has been known (Patent Document 1 (JP-A-2001-286167)). In the motor including the piezoelectric actuator, the projection of the reinforcing plate of the piezoelectric actuator is urged against the driven member by urging means and flexural vibration of the piezoelectric device rotates the driven member in a predetermined direction via the reinforcing plate.
However, even in the above described Patent Document 1, the flexural vibration of the piezoelectric device itself is small and, in order to obtain a larger driving force or amount of rotation (rotation speed), a large piezoelectric actuator with the larger piezoelectric device has been problematic.